Band brake



Aug. 12, 1941.

'0. B. BJORGE BAND BRAKE Filed March 16, 1940' fii mun USU/QR E. EJURE'E5) A TTUR/VE Y Patented Aug. 12, 1941 'UNITED STATES PATENT OFFICE 1Claim.

This invention relates generally to hoisting or cable winding machinery,and particularly to band brakes for use in connection therewith.

The main object of this invention is to construct a band brake by meansof which the arc of contact can be easily increased from 270 derees to540 degrees or more.

The second object is to provide a band brake especially adapted for useon what are known as loading donkeys or hoists by means of which heavylogs are picked up and placed upon railroad cars or trucks requiringthat the lowering of the logs be performed without undue violence.

The third object is to construct a brake of the class described and forthe purpose set forth in a. manner to prolong the life of the equipment,safeguard the lives and persons of its operators and to reduce theamount of physical effort required to satisfactorily lower a log upon atruck or car,

The fourth object is to so apply the band brake that the wearing. actionwill be exceedingly uniform throughout the entire area of contact.

These and other objects are accomplished in the manner set forth in thefollowing specification as illustrated in the accompanying drawing, inwhich:

Fig. 1 is a fragmentary side elevation of a cable winding mechanismshowing a portion thereof broken away in section along the line l-l inFig. 2.

Fig. 2 is a fragmentary plan of Fig. 1.

Fig. 3 is a fragmentary bottom view of Fig. 1.

Fig. 4 is a fragmentary end elevation of Fig. 1.

Fig. 5 is an enlarged detail of the brake band and the connectingfittings.

Fig. 6 is a side elevation of Fig. 5.

Similar numerals refer to similar parts throughout the several views.

Referring in detail to the drawing, there is shown the side frames I'llwhich are spaced by the cross members ll. Across the frames I is mountedthe transverse drum shaft [2 upon which is mounted a cable winding druml3 upon which is wound a supply of cable [4.

On the cable drum flange I is formed a brake drum [6 which is shown withexcessive breadth for the purposes of illustration. There is also showna brake lever shaft H which is supported in any convenient manner notshown. On the brake shaft I1 is secured the brake rocker l8 and also abrake foot lever I9 by means of which the engineer applies the brakingaction.

The mechanism thus far described is common to numerous forms of cablewinding mechanisms now in use.

Referring particularly to my invention, same will be seen to consist ofa central brake band at whose threaded end 2! passes through the wristpin 22 which forms a part of the brake rocker l8. The threaded portion2| is held in place by means of the nuts 23.

Attached to the central brake band. 20 by means of the bolts 24 is agusset plate 25. A shear lug 26 is secured to the band 20 by means of aweld 21. The lug 26 engages the end 28 of the gusset plate 25. To theportions 29 of the gusset plate 25 are secured by means of the welds 30the lateral brake bands 3|. The ends 32 of the bands 3| are secured tothe cross ties II by means of the bolts 33.

It will be noted that the bands 20 and 3| are wrapped completely aroundthe drum l6 and in addition thereto extend beyond the completecircumference to approximately 540 degrees of the contact circle in theform illustrated. Obviously, this amount can be increased further byrelocating the brake shaft II.

The operation of this form of the device is identical with that of otherband brakes except that far less manual effort and movement are requiredfor a given application than is the case with the ordinary brake bandwhich contacts only 2'70 degrees of the drum circle while unequallydistributing the braking area about this partial circumference of thedrum l6.

While with the ordinary form of brake band the braking action is broughtabout by a direct pressure applied from the band to the drum, in mydevice the bands 2|] and 3| are wrapped around the drum I6 therebygreatly increasing the braking action and uniformly distributing samealong the entire braking area giving the operator a more desirablecontrol over the load with far less effort than is ordinarily requiredby existing mechanisms.

While in some cases it might be desirable to form the members 20 and 3|out of one piece, it will in most cases be found preferable to constructsame somewhat after the fashion illustrated herein.

I claim:

In a band brake of the class described, a pair of brake bands adapted topartially encircle a brake drum and to be secured at one pair of.

ends to an anchor, and having a gusset plate uniting the opposite errdsof the bands, and holding same in spaced relationship, a central bandremovably attached to said gusset plate having a shear lug thereonadapted to engage said gusset plate, and a brake applying means attachedto said central band, said band brake being characterized by having itsfriction surface completely encircling the drum and having means forseparating the joint ends of said bands for construction and assemblingpurposes.

OSCAR B. BJORGE.

